A forensic report has found a British-Pakistani woman suspected to have been the victim of an "honor killing" died an unnatural death through suffocation, Pakistani police say.

Mukhtar Kazam had charged that his wife Samia Shahid, 28, was murdered during a visit to her family in Punjab Province on July 20 because she married him against the family's wishes.

Shahid's father has denied the charge and claimed his daughter died of natural causes.

At a press conference last week, Kazam presented a copy of a postmortem report that said Shahid had marks on her neck, suggesting she had been strangled.

Pakistani investigators appeared to confirm that conclusion on August 3, saying the "death occurred due to asphyxia" after her breathing was choked.

Police said Shahid's divorced first husband, Mohammad Shakeel, her parents, and a cousin are under investigation.

Kazam has described his wife's death as an "honor killing", a near daily occurrence in Pakistan where nearly 500 women are killed each year by relatives who believe they have brought shame on the family.